Combustion engines are pressure-charged with the aid of turbochargers in many cases, in conjunction with motor vehicles, for example. This brings about an increase in the efficiency of the engine. Here, the charge air used for pressure-charging is typically cooled with the aid of the charge air cooler. During the cooling process, the charge air cooler produces condensate.
If a charger, e.g. a turbocharger, in particular an electric turbocharger, is arranged after the charge air cooler in the flow direction, there is the risk that condensate will accumulate ahead of the electric turbocharger. For packaging reasons or reasons of efficient arrangement in terms of volume, in conjunction with the motor vehicle for example, it has proven advantageous to position the electric turbocharger geodetically lower than the inlet manifold, in other words below the inlet manifold, and to connect them via a bypass flow duct. The underlying reason for this is, in particular, that the electric turbocharger is not operated continuously but only in connection with specific usage ranges. However, there is the risk that, when starting the electric turbocharger, the quantity of condensate will exceed the permissible limit for the operation of the electric turbocharger or electric compressor or will reach a value which impairs the service life and functionality of the electric turbocharger.
The use of an electrically operated compressor to increase the boost pressure in a bypass line is disclosed in document EP 1 355 052 B1, for example. In document DE 10 2013 106 820 A1, a rise in a relative air humidity in a multistage turbocharger due to a temperature reduction in an intercooler is counteracted by removing moisture. The moisture removal device has a swirl generating element, which has the effect of removing the moisture via the openings in the outer wall. In documents US 2011/0094219 A1 and US 2004/0079079 A1, condensate is in each case discharged into condensate reservoirs via outer walls.
In document DE 199 11 251 A1, a method and a device for detecting the water content in the compressed air flow is disclosed. In DE 10 2011 089 480 A1, a sensor device for detecting at least one property of a flowing medium, in particular a moisture sensor, is disclosed in conjunction with a charge air cooler. In DE 10 2015 012 830 A1, a cooling device for cooling at least one component of a motor car is disclosed, wherein condensate is removed via a valve arranged at the lowest point.
In addition, if a charger, for example a turbocharger, in particular an electrical turbocharger, is arranged downstream of the charge air cooler in the flow direction, there is a risk that condensate will accumulate in front of the electrical turbocharger. For packaging reasons or to ensure an efficient volumetric arrangement, for example in the context of a motor vehicle, it has proved advantageous to place the electrical turbocharger geodetically lower than the inlet manifold, in other words below the inlet manifold, and connect it via a bypass flow channel. This is because, in particular, the electrical turbocharger is not operated permanently but only in connection with specific areas of application. There is however the danger that, on starting of the electrical turbocharger, the quantity of condensate will exceed the permitted limit for operation of the electrical turbocharger or electrical compressor, or reach a value which adversely affects the life and functionality of the electrical turbocharger.
Use of an electrically powered compressor to increase the charge pressure in a bypass line is described for example in document EP 1 355 052 B1. Document DE 10 2009 011 634 A1 describes a condensate extractor for charge air cooler systems, wherein condensate is discharged from the charge air cooler system into a hose element via a specifically designed orifice. A similar solution is disclosed in DE 10 2009 042 981 A1. Document DE 10 2011 056 617 A1 describes a charge air cooler of a compressor of at least one exhaust gas turbocharger, with charge air to be supplied to an internal combustion machine, wherein at least one bypass line is provided between the inlet side and the outlet side of the charge air cooler, and this bypass line is dimensioned such that because of the pressure fall between the inlet side of the charge air cooler and its outlet side, the condensate accumulating can be discharged in the direction of the outlet side. Document DE 10 2010 007 092 A1 describes an exhaust gas recirculation system for an internal combustion machine with an exhaust gas turbocharger, wherein a discharge is provided for condensate which forms in the charge air cooler. DE 102 38 839 A1 describes a charge air cooler with a condensate discharge opening. DE 10 2012 219 796 A1 discloses a charge air supply system which has a condensate collection region.
Given the background situation described, it is an object of the present description to make available an advantageous device for pressure-charging a combustion engine and an advantageous method. This object is achieved by a device for pressure-charging a combustion engine as recited in the claims, a combustion engine assembly as recited in the claims, a motor vehicle as recited in the claims, and a method for removing condensate as recited in the claims. The dependent claims contain further advantageous examples of the description.
The device according to the description for pressure-charging a combustion engine concerns a combustion engine which comprises at least one compressor, e.g. a turbocharger, at least one charge air cooler, at least one inlet to the combustion engine, and a charger. The compressor, the charge air cooler, the inlet and the charger are connected to one another in terms of flow by flow ducts. In this case, the charge air cooler is arranged downstream of the compressor, and the inlet is arranged downstream of the compressor and of the charge air cooler in the flow direction of the charging fluid, generally the charge air. The charger is connected to the inlet via a bypass flow duct arranged between the compressor and the inlet. The charger is arranged geodetically lower or lower in the vertical direction than the inlet, advantageously below the inlet. A moisture sensor is arranged in the bypass flow duct upstream of the charger. The charger can be designed as a turbocharger, e.g. as an electric turbocharger.
In the context described, it is also an object of the present description to provide an advantageous apparatus for charging an internal combustion machine and an advantageous method. This object is achieved by an apparatus for charging an internal combustion machine, an internal combustion machine arrangement, a motor vehicle, and a method for discharging condensate.
The apparatus according to the description for charging an internal combustion machine relates to an internal combustion machine which comprises at least one compressor, for example a turbocharger, at least one charge air cooler, an inlet and a charger. The compressor, the charge air cooler, the inlet and the charger are connected together fluidically via flow channels. In the flow direction of the charging fluid, for example the charge air, the charge air cooler is arranged downstream of the turbocharger. The inlet is arranged downstream of the charge air cooler. The charger is connected to the inlet via a bypass flow channel arranged between the charge air cooler and the inlet. The device according to the description has the advantage that the quantity of the condensate present ahead of the charger can be measured with the aid of the moisture sensor and the charger can be operated in accordance with the result of measurement.
The present description may provide several advantages. In particular, the approach may allow a turbocharger to be activated when condensate is present to remove the condensate and the turbocharger may be deactivated when condensate is not present to reduce energy consumption. Further, the approach allows condensate to be removed from the engine intake system before large amounts of condensate may be formed in the engine intake system. Further still, the condensate may be removed in a way that reduces the possibility of turbocharger degradation.
The above advantages and other advantages, and features of the present description will be readily apparent from the following Detailed Description when taken alone or in connection with the accompanying drawings.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.
FIGS. 1 and 4-7 are drawn approximately to scale.